|
Ulmus Americana 'Ascendens'
The American elm cultivar ''Ulmus americana'' 'Ascendens', 'Upright American Elm', was cloned c.1910 by Bernard H. Slavin, Superintendent of Parks, Rochester, New York, from a tree growing in Seneca Park, Rochester, and named in 1927 for its narrow oval form. See also the similar cultivars 'Columnaris' and 'Augustine Ascending'. It is not known why such a promising clone as 'Ascendens' appears rare in cultivation, but 'Augustine Ascending' was released at about the same date. Neither Green nor Santamour suggested that they were synonyms. Description The tree has small, fastigiate lateral branches forming a narrow, oval head. Its leaves are similar in shape and texture to those of the parent species, but slightly smaller. Arnold Arboretum, however, report leaves 3 to 6 in. long and 2 to 4 in. wide. The bark remains smooth for longer than usual in the species and its fissures are less deep, while the trunk lacks the marked buttressing of the species. Pests and diseases The c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Americana
''Ulmus americana'', generally known as the American elm or, less commonly, as the white elm or water elm, is a species of elm native to eastern North America, naturally occurring from Nova Scotia west to Alberta and Montana, and south to Florida and central Texas. The American elm is an extremely hardy tree that can withstand winter temperatures as low as −42 ° C (−44 ° F). Trees in areas unaffected by Dutch elm disease (DED) can live for several hundred years. A prime example of the species was the Sauble Elm, which grew beside the banks of the Sauble River in Ontario, Canada, to a height of 43 m (140 ft), with a d.b.h of 196 cm (6.43 ft) before succumbing to DED; when it was felled in 1968, a tree-ring count established that it had germinated in 1701. For over 80 years, ''U. americana'' had been identified as a tetraploid, i.e. having double the usual number of chromosomes, making it unique within the genus. However, a study published in 2011 by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher learning in the United States and one of the most prestigious and highly ranked universities in the world. The university is composed of ten academic faculties plus Harvard Radcliffe Institute. The Faculty of Arts and Sciences offers study in a wide range of undergraduate and graduate academic disciplines, and other faculties offer only graduate degrees, including professional degrees. Harvard has three main campuses: the Cambridge campus centered on Harvard Yard; an adjoining campus immediately across Charles River in the Allston neighborhood of Boston; and the medical campus in Boston's Longwood Medical Area. Harvard's endowment is valued at $50.9 billion, making it the wealthiest academic institution in the world. Endowment inco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Elm Cultivar
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verticillium Wilt
Verticillium wilt is a wilt disease affecting over 350 species of eudicot plants. It is caused by six species of ''Verticillium'' fungi: ''V. dahliae'', ''V. albo-atrum'', ''V. longisporum'', ''V. nubilum'', ''V. theobromae'' and ''V. tricorpus''. Many economically important plants are susceptible including cotton, tomatoes, potatoes, oilseed rape, eggplants, peppers and ornamentals, as well as others in natural vegetation communities. Many eudicot species and cultivars are resistant to the disease and all monocots, gymnosperms and ferns are immune. Signs are superficially similar to ''Fusarium'' wilts. There are no fungicides characterized for the control of this disease but soil fumigation with chloropicrin has been proven successful in dramatically reducing ''Verticillium'' wilt in diverse crops such as vegetables using plasticulture production methods, and in non-tarped potato production in North America . Additional strategies to manage the disease include crop rotation, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popillia Japonica
The Japanese beetle (''Popillia japonica'') is a species of scarab beetle. The adult measures in length and in width, has iridescent copper-colored elytra and a green thorax and head. It is not very destructive in Japan (where it is controlled by natural predators), but in North America and some regions of Europe is a noted pest to roughly 300 species of plants, including rose bushes, grapes, hops, canna, crape myrtles, birch trees, linden trees, and others. The adult beetles damage plants by skeletonizing the foliage (i.e., consuming only the material between a leaf's veins) as well as, at times, feeding on a plant's fruit. The subterranean larvae feed on the roots of grasses. Description Adult ''P. japonica'' measure in length and in width, with iridescent copper-colored elytra and green thorax and head. A row of white tufts (spots) of hair project from under the wing covers on each side of the body. Distribution ''Popillia japonica'' is native to Japan, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthogaleruca Luteola
''Xanthogaleruca luteola'', commonly known as the elm-leaf beetle, is a beetle species in the family Chrysomelidae that is native to Europe but invasive in other parts of the world.http://cisr.ucr.edu/elm_leaf_beetle.html - Center for Invasive Species Research Description The imago (adult beetle) is 6–8 mm in length, and ranges from yellow to green in colour, with a spot on its head, an hourglass mark and two spots on the pronotum, and a broad, dark stripe along the edge of each elytron. The larvae are usually black, occasionally black and yellow, with multiple rows of dots on the back and on the sides and < 13 mm long. The pupae are orange-yellow with black chaetae. The ova are yellow, and laid in spindle-like clusters of < 25 on the undersides of the elm leaves. Distribution These beetles are common in the Western Palearctic realm from Portugal to Central Asia. Indigenous to Europe, they were accidentally introduced to North America and Austra ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elm Yellows
Elm yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts."Elm Yellows." Elmcare.Com. 19 Mar. 2008 . Elm yellows, also known as elm phloem necrosis, is very aggressive, with no known cure. Elm yellows occurs in the eastern United States, and southern Ontario in Canada. It is caused by phytoplasmas which infect the phloem (inner bark) of the tree.Price, Terry. "Wilt Diseases." Forestpests.Org. 23 Mar. 2005. 19 Mar. 2008 . Similar phytoplasmas, also known confusingly as 'Elm yellows', also occur in Europe.Conti, M., D'Agostino, G., Mittembergher, L. (1987) A recent epiphytotic of elm yellows in Italy. ''Proceedings of the 7th Congress of the Mediterranean Phytopathological Union'', 208–209. Consejeria de Agricultura y Pesca de la Junta de Andalucia, Granada, Spain Infection and death of the phloem effectively girdles the tree and stops the flow of water and nutrients. The disease affects both wild-growing and cultivated trees. Importance Elms are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch Elm Disease
Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America, Europe, and New Zealand. In these regions it has devastated native populations of elms that did not have resistance to the disease. The name "Dutch elm disease" refers to its identification in 1921 and later in the Netherlands by Dutch phytopathologists Marie Beatrice Schol-Schwarz, Bea Schwarz and Christine Buisman, who both worked with professor Johanna Westerdijk. The disease affects species in the genera ''Ulmus'' and ''Zelkova''; therefore it is not specific to the Ulmus × hollandica, Dutch elm hybrid. Overview Dutch elm disease (DED) is caused by ascomycete microfungi. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arnold Arboretum
The Arnold Arboretum of Harvard University is a botanical research institution and free public park, located in the Jamaica Plain and Roslindale neighborhoods of Boston, Massachusetts. Established in 1872, it is the oldest public arboretum in North America. The landscape was designed by Charles Sprague Sargent and Frederick Law Olmsted and is the second largest "link" in the Emerald Necklace. The Arnold Arboretum's collection of temperate trees, shrubs, and vines has a particular emphasis on the plants of the eastern United States and eastern Asia, where arboretum staff and colleagues are actively sourcing new material on plant collecting expeditions. The arboretum supports research in its landscape and in its Weld Hill Research Building. History The Arboretum was founded in 1872 when the President and Fellows of Harvard College became trustees of a portion of the estate of James Arnold (1781–1868), a whaling merchant from New Bedford, Massachusetts. Arnold specified that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Elm
''Ulmus americana'', generally known as the American elm or, less commonly, as the white elm or water elm, is a species of elm native to eastern North America, naturally occurring from Nova Scotia west to Alberta and Montana, and south to Florida and central Texas. The American elm is an extremely hardy tree that can withstand winter temperatures as low as −42 ° C (−44 ° F). Trees in areas unaffected by Dutch elm disease (DED) can live for several hundred years. A prime example of the species was the Sauble Elm, which grew beside the banks of the Sauble River in Ontario, Canada, to a height of 43 m (140 ft), with a d.b.h of 196 cm (6.43 ft) before succumbing to DED; when it was felled in 1968, a tree-ring count established that it had germinated in 1701. For over 80 years, ''U. americana'' had been identified as a tetraploid, i.e. having double the usual number of chromosomes, making it unique within the genus. However, a study published in 2011 by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Shaw Green
Peter Shaw Green (11 September 1920–17 August 2009) was an English botanist. Early life Green was born in Rochester, Kent, the youngest son of John and Elizabeth (née Hainsworth) Green, his father a civilian engineer with the Royal Air Force. He was educated at Taunton School, before studying botany at King's College London. His studies were interrupted by the Second World War, in which he served as an Adjutant (Captain) in the Northumberland Fusiliers, initially training recruits to shoot, but later joining his regiment in Italy, where he contracted typhoid. Upon recovery, he was despatched to Greece. In 1946, while still in uniform, he married Winifred Brown, whom he had met at King's College before the war. After demobilization, he returned to his studies at King's College. Career After graduation, Green was appointed Assistant Lecturer at Birmingham University before joining the Royal Botanic Garden, Edinburgh in 1952. In 1961, he moved to the Arnold Arboretum of Harvar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Americana 'Augustine'
The American elm cultivar ''Ulmus americana'' 'Augustine', originally called 'Augustine Ascending', was cloned by Archie M. Augustine of the Augustine Nursery of Bloomington, Illinois, from a nursery seedling planted in 1927 in Normal, Illinois, and found to be columnar in habit. See also the similar cultivars 'Columnaris' and 'Ascendens'. It is not known why such a promising clone as 'Ascendens' appears rare in cultivation, but 'Augustine Ascending' was released at about the same date. Neither Green nor Santamour suggested that they were synonyms. Description 'Augustine' is a vigorous fastigiate tree distinguished by its thicker branches and larger, more deeply toothed leaves. ''Flower and Garden Magazine'' reported that the original tree was still standing in 1959 and – erroneously – that the cultivar did not produce seed. The deep root-system of the cultivar was said to be less likely to damage sidewalks than American elm generally. Pests and diseases 'Augustine' ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
